Conventional graphical human-computer interfaces are referred to as “WIMP” interfaces, for the Windows, Icons, Menus, and mouse Pointers they provide and employ. Traditional WIMP based modalities, when applied to interactions in virtual 3-D environments, are completely oblivious to users' spatial interaction capabilities and the affordances of physical objects in the surrounding environment. Instead they rely on minimalistic user motions to accomplish large scale 3-D interactive tasks. As a result, a large part of the input effort users apply while performing 3-D tasks are based on their cognitive perceptions and processes. In addition, the lack of expressiveness in these modalities requires the presence of an extensive set of non-intuitive control widgets (e.g., buttons, icons, menus etc.) for providing spatial inputs. Such mechanisms make shape modeling tasks difficult to learn and apply.